Take Cover: How Cover Crops Improve Your Land
As climate change, disease, and a variety of other factors jeopardize the future of honey bees, farmers are implementing practices on their own land to support bees and other pollinators. This includes planting cover crops.
What Are Cover Crops?
Cover crops are crops planted to improve soil quality and promote sustainability rather than to produce fruits or vegetables. They include grasses, legumes, and other green plants that increase plant and animal biodiversity. Farmers choose what specific cover crops to use based on what benefits they look for, such as better soil health, weed control, reduced soil erosion, and more, which influences when these crops are planted during the year.
2017 saw a 50% increase in cover crops over the previous five years. During that time period, eight states doubled their cover crop acreage, and there was a 15.2% increase in the number of farms that planted cover crops.
After five consecutive years of cover crop use, farmers can expect their corn yield to increase 3% and their soybean yield to increase 4.9%. Farmers reported a 9.6% increase in corn yield and 11.6% increase in soybean yield in 2012 when they used cover crops.
The Different Types of Cover Crops
Legumes and non-legumes compose the majority of cover crops.
- Legumes consist of “red clover, crimson clover, vetch, peas, and beans.”
- Non-legumes consist of “cereals (rye, wheat, barley, oats, triticale), forage grasses (annual ryegrass), and broadleaf species (buckwheat, mustards and brassicas, including the forage radish).”
Some farmers employ “cocktails,” or cover crop mixtures, to attain multiple goals. Although these combinations may result in many benefits, they often are more expensive and complex to maintain.
Benefits of Cover Crops
Protection Against Soil Erosion and Runoff
Cover crops protect against soil erosion and water and snow runoff by providing a protective canopy over the ground, serving as a barrier from the rain and wind that breaks down the soil. As a result, pesticides and herbicides are less likely to move around freely and affect streams, rivers, and other bodies of water. In addition, helpful nutrients are less likely to be washed away from the ground.
Improved Soil Health
Bacterial and fungal diseases present in the soil can also be reduced with the planting of cover crops. Cover crops also enhance soil quality without the need for chemicals by adding nutrients back into the soil and regulating nitrogen levels (called scavenging when there is excess nitrogen). Through biological nitrogen fixation, soil fertility is improved without the need for more nitrogen fertilizer. In addition, future crops use the trapped nutrients from the manure, mineralized organic nitrogen, or underutilized fertilizer stored by cover crops, which also reduces nutrient runoff.
Improved Water-Holding Abilities
Gradually, the soil quality will develop because of the increase in organic matter that improves moisture- and nutrient-holding capabilities (the crops also create pores in the soil to filter water deeper), which in turn helps the infiltration of the water through the ground and reduces soil compaction. Especially with unpredictable weather, these moisture- and water-holding abilities help the crops persevere through drought and dry weather by retaining liquid.
Protection Against Unwanted Pests and Weeds
Unwanted pests, weeds, and diseases are deterred by cover crops and beckon needed insects and pollinators, increasing biodiversity. Acting as food sources and habitats that attract insects and bees, birds and other small animals will be attracted as well.
Cover Crops and Their Unique Benefits
Legumes are known for reduced erosion and promotion of biodiversity. They are better at reducing levels of nitrogen from fertilizer after cover crops are planted rather than reducing excess nitrogen left over from cash crops. Non-legumes are known for subduing weeds, adding nutrients, and increasing organic matter in the soil. Grasses are specifically skilled at decreasing excess amounts of nitrogen in the soil from nitrogen fertilizer. Other crops and their benefits include:
- “Rye: Also known as winter rye or cereal rye, this cover crop is often used to loosen compact soil and suppress weeds.
- Buckwheat: Fast-growing buckwheat helps prevent erosion and suppress weeds.
- Clover: Clover is great for fixing nitrogen in the soil and adding fertility.
- Sorghum: This hybrid cover crop grows quickly, adds biomass, and suppresses weeds.
- Hairy vetch: Vetch adds nitrogen and is a good overwinter crop for northern climates.”
When Should I Plant Cover Crops?
Cover crops are usually planted in the off-season to prepare for the planting of the cash crop. Developing a plan to incorporate the cover crop into your rotation or a new rotation is complex and requires research to ensure the health of both the cover and cash crops.
Should You Plant Cover Crops?
Cover crops don’t immediately produce benefits—they are long-term investments where benefits take one to several years to surface. One year usually sees improved grazing and weed suppression, but it takes two to three years to see improved soil quality. However, if you are interested in making your farming more sustainable and want to reap several of these benefits, you should research which cover crops work best for you.